Recently setup my media centre to play HDTV content using the nVidia proprietary driver with XvMC. There is not a lot of documentation on how to do this so below is how I got the Xorg part working.

This HowTo assumes that you have installed all the required software including your xorg server (with evdev and hal enabled) Desktop Environment / Window Manager and Media Centre Software and necessary kernel modules to get your DVB card recognised in your chosen Media Centre Software and the correct nVidia proprietry driver for your graphics card. All that is left for you to do is get the correct xorg.conf file.

It is quite difficult setting up the nvidia proprietary driver for use on certain Plasma TVs as there is not a lot of documentation on the web for it and a lot of older / cheaper plasma TVs run at a very low refresh rate. I did however find some help here http://en.gentoo-wiki.com/wiki/MythTV/MythTv/OldSetup and here http://www.mythtv.org/wiki/XvMC#NVIDIA_2. These combined with a little of my own tweaking got the xorg.conf file below to work. The new setup works an absolute treat! Enjoy!